It appears not everybody knows they are public. The NBA releases all the results, by voter, after their awards show. (Why not now for the awards already released, you ask? Because you probably could figure out the other winners ahead of time and not watch the show.) twitter.com/streethistory/…

Or a network entirely, when you consider that ESPN probably has at least 10 and maybe closer to 20 votes. (I believe AP has three, in terms of disclosure, although obviously we all choose independently of one another.)

To those who say players should be voting for All-NBA ... may I remind you that two players cast ballots for Ron Baker, who scored 14 points this season, as a 2019 NBA All-Star.
Many would take it seriously. Some wouldn't, unless ballots were public. And that would never happen.